In an evolution process of a network from a 2G/3G network to an LTE (long term evolution) network, and in a certain period, there is a scenario where the 2G/3G network and the LTE network coexist. In a handover position between the 2G/3G network and the LTE network, when a UE (user equipment) is moved from the 2G/3G network to the LTE network, the UE may initiate a TAU (tracking area update) procedure; when the UE is moved from the 2G/3G network to the LTE network, the UE may initiate a RAU (routing area update) procedure. In order to reduce TAU or RAU caused by the UE in an Idle state due to the change of a RAT (radio access type), an ISR (Idle mode signaling reduction, idle mode signaling reduction) mechanism is introduced. At present, the ISR mechanism between 3GPP (the 3rd generation partnership project) access networks is a double registration mechanism, that is, the UE is registered in two different access networks. In the condition that the ISR mechanism is activated, when the UE is moved from an MME (mobility management entity) to an SGSN (serving GPRS support node), UE context on the MME is not deleted. Correspondingly, when the UE is moved from the SGSN to the MME, UE context on the SGSN is not deleted either.
In the scenario where the 2G/3G network and the LTE network coexist, when an SGW (serving gateway) receives downlink data or signaling, if the ISR mechanism is activated, the SGW sends a DDN (downlink data notification) message to the MME and the SGSN, and the SGSN and the MME may page the UE at the same time.
If the UE camps on the LTE network, the network side may set up a corresponding bearer according to context of the UE saved on the MME. If the UE camps on the 2G/3G network, the network side may set up a corresponding bearer according to context of the UE saved on the SGSN.
The prior art has at least the following problem. In the state that the ISR mechanism is activated and the radio access type of the UE is changed, paging the UE by the network side may lead to a loss of a part of bearers or setup of a bearer with inconsistent bearer contexts at two ends, thereby seriously affecting normal use of a service, and bringing bad user experience.